This invention relates to harvesting machine conveyors and more particularly to the construction of a retracting finger assembly in a beater-like conveying element.
It is common in combine harvesters to assist the transfer of crop material into a feeder conveyor for delivery to a threshing cylinder by providing, in a gatherer such as a grain cutting platform, a form of beater co-axial and integral with the platform auger and immediately ahead of the feeder conveyor. A common form of beater consists of a rotating and retracting finger arrangement in which a finger crankshaft is fixed inside of and eccentric to a rotating drum. Elongated fingers journaled on the finger crankshaft extend generally radially through guide slots in the surface of the drum so that, as the drum rotates, the fingers are rotated about their shaft and reciprocated in the guide slots due to the eccentricity of the finger shaft with respect to the drum. The arrangement is timed so that the fingers extend to engage crop material and sweep it under the drum into the feeder conveyor and retract to assist in releasing the material into the feeder conveyor. An arrangement of this kind is shown in U.S. Pat. No. 2,701,634 Carroll.
A combine gatherer platform must operate in a variety of soil and crop conditions and is often operated at near maximum capacity so that its conveying elements, including a platform beater portion and fingers, are subjected to heavy and fluctuating loading, to abrasion from dirt gathered in with the crop, and possibly, to direct mechanical damage from inadvertent feeding of foreign bodies such as rocks and scrap metal into the conveyor system. There is thus a relatively frequent need to remove and reinstall platform auger finger assemblies, to replace worn out finger bearings and/or broken fingers.
In the conventional construction of platform augers, the auger assembly, including a central drum portion, is journaled on a fixed transverse shaft supported in the frame of the platform and provided with suitable drive means. In the beater area of the platform auger, the fixed crankshaft is offset for journaling the finger assemblies with required eccentricity. Generally, there is a releasable connection between the offset crankshaft portion and the remainder of the shaft. Finger bearings are of one piece and to replace a bearing or complete finger assembly, it is necessary to detach at least one end of the shaft offset portion and remove a number of finger assemblies by sliding them from the shaft to gain access to the damaged one. Access for this disassembly operation is gained through hand or access holes in the auger tube, normally closed by removable covers. Replacing finger assemblies or finger bearings in this way is awkward, inconvenient and time consuming.
An attempt to make finger assembly service and repair more convenient is disclosed in U.S. Pat. No. 3,142,375 Luke. By providing a two-piece bearing construction, Luke makes it unnecessary to disconnect the finger crankshaft but suggests a finger construction requiring the considerable dexterity involved in: positioning two unconnected bearing halves on the finger crankshaft; and aligning and holding them opposite one another on the shaft while maneuvering into place a pair of loose spring clamps, one for each end of the bearing. This must be accomplished while reaching through an access opening of necessarily limited size. In addition, Luke suggests fingers rigidly secured to one of the bearing halves, making independent repair or replacement of the respective bearing and finger portions of an assembly impractical or uneconomic.